/* TechForum - Modern CSS Styles */

/* ===== CSS Variables ===== */
:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #64748b;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #3b82f6;
    
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-card: #1e293b;
    --bg-hover: #334155;
    
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    
    --border: #334155;
    --border-light: #475569;
    
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -2px rgba(0, 0, 0, 0.2);
    
    --radius: 12px;
    --radius-sm: 8px;
    --radius-lg: 16px;
    
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Reset & Base Styles ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, var(--bg-primary) 0%, #1a1f3a 100%);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    color: var(--primary-light);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--primary);
}

/* ===== Container ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* ===== Navigation Bar ===== */
.navbar {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
}

.nav-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.logo-icon {
    font-size: 1.8rem;
}

.nav-links {
    display: flex;
    gap: 1.5rem;
    flex: 1;
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.nav-link:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
}

.nav-auth {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-menu {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.5rem 1rem;
    background: var(--bg-tertiary);
    border-radius: var(--radius);
}

.user-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    color: white;
}

.username {
    font-weight: 600;
    color: var(--text-primary);
}

/* ===== Main Content ===== */
.main-content {
    min-height: calc(100vh - 200px);
    padding: 2rem 0;
}

/* ===== Hero Section ===== */
.hero {
    text-align: center;
    padding: 3rem 0;
    margin-bottom: 2rem;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-light), var(--primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* ===== Statistics Grid ===== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.stat-card {
    background: var(--bg-card);
    padding: 1.5rem;
    border-radius: var(--radius);
    text-align: center;
    border: 1px solid var(--border);
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.stat-icon {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-light);
    display: block;
    margin-bottom: 0.25rem;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* ===== Section ===== */
.section {
    margin-bottom: 3rem;
}

.section-title {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

/* ===== Categories Grid ===== */
.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.category-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    display: flex;
    gap: 1rem;
    transition: var(--transition);
    color: var(--text-primary);
}

.category-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.category-icon {
    font-size: 2.5rem;
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
}

.category-info h3 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.category-info p {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.75rem;
}

.category-stats {
    display: flex;
    gap: 1rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* ===== Threads List ===== */
.threads-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.thread-item {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    display: grid;
    grid-template-columns: auto 1fr auto auto;
    gap: 1.5rem;
    align-items: center;
    transition: var(--transition);
}

.thread-item:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow);
}

.thread-icon {
    font-size: 1.5rem;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
}

.thread-content {
    flex: 1;
}

.thread-content h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.thread-content h3 a {
    color: var(--text-primary);
}

.thread-content h3 a:hover {
    color: var(--primary-light);
}

.thread-meta {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.thread-stats {
    display: flex;
    gap: 1.5rem;
}

.stat {
    text-align: center;
}

.stat-value {
    display: block;
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary-light);
}

.stat-label {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.thread-last-reply {
    text-align: right;
    font-size: 0.85rem;
}

.last-reply-text {
    color: var(--text-muted);
}

.last-reply-user {
    font-weight: 600;
    color: var(--text-primary);
}

.last-reply-time {
    color: var(--text-secondary);
}

/* ===== Badges ===== */
.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 600;
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.badge-admin {
    background: linear-gradient(135deg, var(--danger), #dc2626);
}

.badge-mod {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
}

.badge-warning {
    background: var(--warning);
    color: var(--bg-primary);
}

.badge-danger {
    background: var(--danger);
}

/* ===== Buttons ===== */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    font-size: 0.95rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.btn-secondary:hover {
    background: var(--bg-hover);
}

.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-danger:hover {
    background: #dc2626;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-block {
    display: block;
    width: 100%;
}

.btn-link {
    padding: 0.25rem 0.5rem;
    font-size: 0.85rem;
}

.btn-danger-link {
    color: var(--danger);
}

.btn-danger-link:hover {
    color: #dc2626;
}

/* ===== Forms ===== */
.form-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    max-width: 800px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-primary);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.75rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group textarea {
    resize: vertical;
}

.form-help {
    display: block;
    margin-top: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.form-actions {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

/* ===== Auth Pages ===== */
.auth-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: calc(100vh - 250px);
}

.auth-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 3rem;
    max-width: 450px;
    width: 100%;
    box-shadow: var(--shadow-lg);
}

.auth-card h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    text-align: center;
}

.auth-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.auth-form {
    margin-bottom: 1.5rem;
}

.auth-footer {
    text-align: center;
    color: var(--text-secondary);
}

/* ===== Alerts ===== */
.alert {
    padding: 1rem 1.25rem;
    border-radius: var(--radius-sm);
    margin-bottom: 1.5rem;
    border-left: 4px solid;
}

.alert-error {
    background: rgba(239, 68, 68, 0.1);
    border-color: var(--danger);
    color: #fca5a5;
}

.alert-success {
    background: rgba(16, 185, 129, 0.1);
    border-color: var(--success);
    color: #6ee7b7;
}

.alert-warning {
    background: rgba(245, 158, 11, 0.1);
    border-color: var(--warning);
    color: #fcd34d;
}

.alert-info {
    background: rgba(59, 130, 246, 0.1);
    border-color: var(--info);
    color: #93c5fd;
}

/* ===== Breadcrumb ===== */
.breadcrumb {
    display: flex;
    gap: 0.5rem;
    align-items: center;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
    color: var(--text-muted);
}

.breadcrumb a {
    color: var(--text-secondary);
}

.breadcrumb a:hover {
    color: var(--primary-light);
}

/* ===== Page Header ===== */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.page-header h1 {
    font-size: 2rem;
}

/* ===== Category Header ===== */
.category-header {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    margin-bottom: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.category-info-large {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.category-icon-large {
    font-size: 4rem;
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-tertiary);
    border-radius: var(--radius);
}

.category-info-large h1 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.category-info-large p {
    color: var(--text-secondary);
}

/* ===== Thread Page ===== */
.thread-header {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    margin-bottom: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: start;
}

.thread-header h1 {
    font-size: 2rem;
    margin-bottom: 0.75rem;
}

.thread-actions {
    display: flex;
    gap: 0.5rem;
}

/* ===== Posts ===== */
.post-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    margin-bottom: 1rem;
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 1.5rem;
}

.original-post {
    border-left: 4px solid var(--primary);
}

.post-author {
    text-align: center;
}

.author-avatar {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: 700;
    margin: 0 auto 1rem;
    color: white;
}

.author-name {
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
}

.author-role {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.role-user {
    background: var(--bg-tertiary);
}

.role-moderator {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
}

.role-admin {
    background: linear-gradient(135deg, var(--danger), #dc2626);
}

.author-meta {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.post-body {
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.post-body code {
    background: var(--bg-tertiary);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: 'Monaco', 'Consolas', monospace;
    font-size: 0.9em;
}

.post-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
    font-size: 0.85rem;
    color: var(--text-muted);
}

.post-date {
    color: var(--text-muted);
}

/* ===== Reply Form ===== */
.reply-form-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 2rem;
    margin-top: 2rem;
}

.reply-form-card h3 {
    margin-bottom: 1.5rem;
}

/* ===== Pagination ===== */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    margin-top: 2rem;
}

.pagination-info {
    color: var(--text-secondary);
}

/* ===== Empty State ===== */
.empty-state {
    text-align: center;
    padding: 3rem;
    color: var(--text-secondary);
}

.empty-state p {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
}

/* ===== Footer ===== */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: 3rem 0 1.5rem;
    margin-top: 4rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.footer-section h4 {
    font-size: 1rem;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.footer-section p {
    color: var(--text-secondary);
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: var(--text-secondary);
}

.footer-section ul li a:hover {
    color: var(--primary-light);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border);
    color: var(--text-muted);
}

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }
    
    .nav-content {
        flex-wrap: wrap;
    }
    
    .nav-links {
        order: 3;
        width: 100%;
    }
    
    .thread-item {
        grid-template-columns: auto 1fr;
        gap: 1rem;
    }
    
    .thread-stats,
    .thread-last-reply {
        grid-column: 2;
    }
    
    .post-card {
        grid-template-columns: 1fr;
    }
    
    .category-header {
        flex-direction: column;
        gap: 1.5rem;
    }
    
    .thread-header {
        flex-direction: column;
        gap: 1.5rem;
    }
    
    .page-header {
        flex-direction: column;
        gap: 1rem;
        align-items: flex-start;
    }
}

/* ===== Animations ===== */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.thread-item,
.category-card,
.post-card {
    animation: fadeIn 0.3s ease-out;
}